ECG in Clinical Practice Flashcards

How does an ECG differ in pediatric patients compared to adults?

Answer: Children normally have faster heart rates, right axis deviation in infancy, and different normal values for intervals

Pediatric ECGs have age-dependent normal values: faster resting heart rates, right axis deviation in neonates (transitioning to normal axis), shorter intervals, and different voltage criteria for hypertrophy.

What is Holter monitoring?

Answer: Continuous ambulatory ECG recording over 24-48 hours to detect intermittent arrhythmias

Holter monitoring provides continuous ECG recording during normal daily activities for 24-48 hours (or longer with event recorders), capturing intermittent arrhythmias that might not appear during a brief in-office ECG.

What ECG changes are expected during an exercise stress test?

Answer: Increasing heart rate, ST segment changes indicating ischemia, and arrhythmia detection under exertion

Exercise stress testing monitors ECG for ischemic changes (ST depression >1mm), arrhythmias, and blood pressure response during graded exercise to evaluate for coronary artery disease and exercise-induced arrhythmias.

What is the significance of pathological Q waves on an ECG?

Answer: They indicate previous myocardial infarction with irreversible tissue death in the affected area

Pathological Q waves (>1mm wide, >25% of R wave height) indicate prior transmural myocardial infarction where dead heart muscle has been replaced by scar tissue, serving as a permanent marker of past heart attack.

How does right bundle branch block (RBBB) appear on an ECG?

Answer: Wide QRS (>120ms) with rsR' pattern in V1 (rabbit ears) and wide S wave in V6

RBBB shows widened QRS >120ms, an rsR' (M-shaped) pattern in V1-V2, and a wide, slurred S wave in leads I and V6, reflecting delayed right ventricular depolarization.

What does an ECG technologist do when encountering a life-threatening rhythm?

Answer: Immediately alert the supervising physician or activate the emergency response system per facility protocol

When a life-threatening rhythm is identified (VF, VT, asystole, complete heart block), the technologist must immediately alert the physician or activate the emergency response system while maintaining patient safety.